Non-adiabatic pumping through interacting quantum dots

TL;DR

This paper investigates non-adiabatic charge and spin pumping in interacting quantum dots, revealing frequency-dependent phase shifts that enable single-parameter and pure spin pumping within certain frequency regimes.

Contribution

It provides an exact resummation of all orders in pumping frequency for weak tunnel coupling, uncovering novel non-adiabatic effects in quantum dot transport.

Findings

Frequency-dependent phase shifts in charge and spin currents

Single-parameter pumping enabled by phase shifts

Pure spin currents without charge flow

Abstract

We study non-adiabatic two-parameter charge and spin pumping through a single-level quantum dot with Coulomb interaction. For the limit of weak tunnel coupling and in the regime of pumping frequencies up to the tunneling rates, $\Omega \lesssim \Gamma/\hbar$, we perform an exact resummation of contributions of all orders in the pumping frequency. As striking non-adiabatic signatures, we find frequency-dependent phase shifts in the charge and spin currents, which allow for an effective single-parameter pumping as well as pure spin without charge currents.